Viewed in the light most favorable to the verdict, the evidence authorized a rational trier of fact to find Kendall guilty beyond a reasonable doubt. Jackson v. Virginia, 443 U. S. 307 (99 SC 2781, 61 LE2d 560) (1979). However, the record contains no written waiver by Kendall of his right to be tried by a jury, as required by OCGA 40-13-23 in order for the probate court to have jurisdiction to dispose of the case, and Kendall's conviction must therefore be reversed. Rustin v. State, 192 Ga. App. 775 (2) (386 SE2d 535) (1979). See also Snellings v. State, 194 Ga. App. 552 (391 SE2d 36) (1990).